Detection Of Intracranial Hemorrhage Research Articles

Transcranial ultrasound hemorrhage detector

The present state-of-the-art technology in clinical neurosonography requires an acoustic window to achieve a sufficient signal-to-noise ratio (SNR) for detection of intracranial hemorrhage (ICrH). Conventional clinical practices use ultrasound in the range of 2–10 MHz to image and diagnose patients, a frequency range that is too high to produce high-quality transcranial images. This study examined the use of ultrasound frequencies on the order of 0.5 MHz, applied through the skull bone, to detect ICrH. We demonstrated with exvivo human skull specimens, ex vivo animal blood, and soft tissue-mimicking phantoms that a single element ultrasonic transducer can likely be used to detect the presence of ICrH immediately adjacent to the skull bone. The lower frequency design of the transducer together with optimized aperture geometry demonstrated efficient signal transmission through the skull bone with a focal depth optimized for intracranial anatomy. The identification of hemorrhage-brain interfaces was demonstrated with bench-top experiments that mimicked the clinical conditions of acute epi- and subdural hemorrhage. Finally, the device limitations were demonstrated through positive predictive value analysis.

Value of Repeat Head Computed Tomography after Traumatic Brain Injury: Systematic Review and Meta-Analysis

Diagnosis and management of traumatic brain injury (TBI) is crucial to improve patient outcomes. While initial head computed tomography (CT) scan is the optimum tool for quick and accurate detection of intracranial hemorrhage, the guidelines on use of repeat CT differ among institutions. Three systematic reviews have been conducted on a similar topic; none have performed a comprehensive meta-analysis of all studies. Search of Medline, the Cochrane Library database, and Clinicaltrials.gov , and a hand search of conference abstracts and references for all completed studies reporting data on change in management following repeat CT was conducted. Two authors reviewed all studies and extracted data using a standardized form. A proportional meta-analysis was conducted using the random-effects model for outcomes related to any change in management following repeat CT. Any change in management included intracranial intervention, change in intracranial pressure monitoring, and/or administration of drug therapy. Search results yielded 6982 references. In all, 41 studies enrolling 10,501 patients were included. Change in management following repeat CT was reported in 13 prospective and 28 retrospective studies and yielded a pooled proportion of 11.4% (95% confidence interval [CI] 5.9-18.4) and 9.6% (95% CI 6.5-13.2), respectively. In a subgroup analysis of mild TBI patients (Glasgow Coma Scale score 13 to 15), five prospective and nine retrospective studies reported on change in management following repeat CT with the pooled proportion across prospective studies at 2.3% (95% CI 0.3-6.3) and across retrospective studies at 3.9% (95% CI 2.3-5.7), respectively. The evidence suggests that repeat CT in patients with TBI results in a change in management for only a minority of patients. Better designed studies are needed to address the issue of the value of repeat CT in the management of TBI.

Intracranial Calcifications and Hemorrhages: Characterization with Quantitative Susceptibility Mapping

Purpose To compare gradient-echo (GRE) phase magnetic resonance (MR) imaging and quantitative susceptibility mapping (QSM) in the detection of intracranial calcifications and hemorrhages. Materials and Methods This retrospective study was approved by the institutional review board. Thirty-eight patients (24 male, 14 female; mean age, 33 years ± 16 [standard deviation]) with intracranial calcifications and/or hemorrhages diagnosed on the basis of computed tomography (CT), MR imaging (interval between examinations, 1.78 days ± 1.31), and clinical information were selected. GRE and QSM images were reconstructed from the same GRE data. Two experienced neuroradiologists independently identified the calcifications and hemorrhages on the QSM and GRE phase images in two randomized sessions. Sensitivity, specificity, and interobserver agreement were computed and compared with the McNemar test and k coefficients. Calcification loads and volumes were measured to gauge intermodality correlations with CT. Results A total of 156 lesions were detected: 62 hemorrhages, 89 calcifications, and five mixed lesions containing both hemorrhage and calcification. Most of these lesions (146 of 151 lesions, 96.7%) had a dominant sign on QSM images suggestive of a specific diagnosis of hemorrhage or calcium, whereas half of these lesions (76 of 151, 50.3%) were heterogeneous on GRE phase images and thus were difficult to characterize. Averaged over the two independent observers for detecting hemorrhages, QSM achieved a sensitivity of 89.5% and a specificity of 94.5%, which were significantly higher than those at GRE phase imaging (71% and 80%, respectively; P < .05 for both readers). In the identification of calcifications, QSM achieved a sensitivity of 80.5%, which was marginally higher than that with GRE phase imaging (71%; P = .08 and .10 for the two readers), and a specificity of 93.5%, which was significantly higher than that with GRE phase imaging (76.5%; P < .05 for both readers). QSM achieved significantly better interobserver agreements than GRE phase imaging in the differentiation of hemorrhage from calcification (κ: 0.91 vs 0.55, respectively; P < .05). Conclusion QSM is superior to GRE phase imaging in the differentiation of intracranial calcifications from hemorrhages and with regard to the sensitivity and specificity of detecting hemorrhages and the specificity of detecting calcifications. © RSNA, 2013 Online supplemental material is available for this article.

The value of b0 images obtained from diffusion-weighted echo planar sequences for the detection of intracranial hemorrhage compared with GRE sequence

PurposeOur aim was to evaluate the clinical utility of b0EPI images obtained from diffusion sequence for the detection of the intracranial hemorrhagic lesions, especially acute intracerebral bleeds thereby shorten the scan time particularly in the critical acute cases of stroke. Materials and methodsAmong all consecutive MR brain studies performed in our department last year, we retrospectively selected those who followed the following criteria: (1) clinically suspected or radiographically confirmed acute infarction or hemorrhage. (2) MRI imaging including DWI and T2∗ images. Sensitivity of hemorrhage detection, conspicuity of lesions, and diagnostic certainty were compared between the b0EPI and GRE sequences. ResultsThere were 77 hemorrhagic lesions with a variety of pathogeneses in various locations. 76/77 (98.7%) of these lesions were hemorrhagic (hypointense) on the GRE sequences, whereas 61 (79.2%) were characterized as hemorrhagic on b0EPI images, and 16 (20.8%) were not detected. The overall difference in hemorrhage conspicuity/diagnostic certainty between GRE and b0EPI sequences was statistically significant (P<.05). Conclusionb0EPI sequence, although shorter in acquisition time, was inferior to GRE imaging in the detection of acute and chronic intracerebral hemorrhage.

196 Improved Detection of Intracranial Hemorrhage in Term and Preterm Neonates Using Susceptibility Weighted Imaging

Background and aimsMagnetic resonance imaging (MRI) at term age has been reported to be superior to cranial ultrasound (cUS) in detecting white matter abnormalities. The aim of this retrospective study...

Accuracy of head ultrasound for the detection of intracranial hemorrhage in preterm neonates: Comparison with brain MRI and susceptibility-weighted imaging

To evaluate the sensitivity and specificity of head ultrasound (HUS) in the detection of intracranial hemorrhage in premature neonates compared with brain MRI using susceptibility-weighted imaging (SWI). Ultrasound (US) and MRI scans of the brain using SWI in premature neonates were retrospectively evaluated for grade I-III germinal matrix hemorrhage (GMH), periventricular hemorrhagic infarction (PVHI), intra-axial hemorrhage other than PVHI, extra-axial hemorrhage in each cerebral hemisphere and cerebellar hemorrhage in each cerebellar hemisphere. The impact of these hemorrhagic findings on short-term clinical management was also reviewed. Twelve neonates (mean age: 9.8 days; range: 3-23 days) with a mean gestational age of 32.8 weeks (range: 29.6-35.4 weeks) were included in the study. HUS had high sensitivity (100%) and specificity (93.3%) in detecting grade III GMH using SWI as a reference, but poor sensitivity (0%) in the detection of intraventricular hemorrhage with normal-sized ventricles (grade II GMH). US was not sensitive in detecting either small cerebellar or extra-axial hemorrhage. HUS was highly sensitive and specific in the evaluation of grade III GMH, whereas SWI was superior to HUS in detecting small intra-axial or extra-axial hemorrhage, and had no impact on short-term management. Given the low cost, lack of radiation and advantages of bedside evaluation, HUS should continue to be the first line of imaging for brain injury in the evaluation of premature neonates with suspected intracranial hemorrhage. However, the usefulness of SWI for predicting long-term neurological outcomes has yet to be determined.

Intracranial hemorrhage detection using spatial fuzzy c-mean and region-based active contour on brain CT imaging

Intracranial hemorrhage (ICH) detection is the primary task for the patients suffering from neurological disturbances and head injury. This paper presents a segmentation technique that combines the features of fuzzy c-mean (FCM) clustering and region-based active contour method. In the suggested method, the fuzzy membership degree from FCM clustering is first used to initialize the active contour, which propagates for the detection of the desired object. In addition to active contour initialization, the fuzzy clustering is also used to estimate the contour propagation controlling parameters. The level set function as used by active contour in the proposed method does not need re-initialization process; thus, it fastens the convergent speed of the contour propagation. The efficacy of the suggested method is demonstrated on a dataset of 20 brain computed tomography (CT) images suffered with ICH. Experimental results show that the proposed method has advantages in accuracy in comparison with standard region growing method and FCM for the detection of hemorrhage from brain CT images.

The Utility of Near Infrared Spectroscopy in Detecting Intracranial Hemorrhage in Children

A prospective case-control study was conducted in a tertiary care pediatric intensive care unit (PICU) to evaluate the use of near infrared spectroscopy (NIRS) for the detection of intracranial hemorrhage (ICH) in children. Subjects 0-14 years of age who had a computed tomography (CT) scan of the head performed as part of clinical care were eligible for enrollment. The children were stratified into two groups based on whether the CT was normal or abnormal. Children in the abnormal imaging cohort were further divided into those with ICH and those with other abnormalities of the brain parenchyma (contusions, diffuse axonal injury [DAI], or cerebral edema) or fractures. NIRS measurements were performed on all subjects within 24 h of head CT. The NIRS operator was blinded to the presence or absence of ICH. NIRS measurements were performed in eight different scalp locations (four bilaterally). A total of 103 measurements were made. The optical density (OD) was automatically calculated by comparing the reflected and diffused optical signal. A ΔOD>0.2 between hemispheres in any scalp location was considered abnormal. NIRS was performed in a total of 28 subjects: 7 had normal imaging and 21 had abnormal imaging. Of those with abnormal imaging, 12 had ICH. The sensitivity and specificity of NIRS at detecting ICH was 1.0 and 0.8, respectively. The positive and negative predictive values were 0.8 and 1.0, respectively. In conclusion, NIRS correctly identified all cases of ICH in this pilot study. Our preliminary results suggest that NIRS may be beneficial in the evaluation of a child with possible ICH.

The role of neuroradiology in intracerebral haemorrhage

The neuroradiologist plays a fundamental role in evaluating cerebral haemorrhage, from the clinical suspect until the final diagnosis.The neuroradiologist’s role consists not only in highlighting the presence of an haemorrhage, but also in specifying its localization and its nature, and in assessing, together with the neurosurgeon, the adequate treatment.With the aid of some case reports, this article underlines the role of neuroradiologist in the diagnostic process. For each case report discussed, computerised tomography (CT) and digital subtraction angiography (DSA) findings are given, to better highlight the diagnostic role of these techniques in the detection and characterization of intracranial haemorrhage.

The role of neuroradiology in intracerebral haemorrhage

The neuroradiologist plays a fundamental role in evaluating cerebral haemorrhage, from the clinical suspect until the final diagnosis.The neuroradiologist’s role consists not only in highlighting the presence of an haemorrhage, but also in specifying its localization and its nature, and in assessing, together with the neurosurgeon, the adequate treatment.With the aid of some case reports, this article underlines the role of neuroradiologist in the diagnostic process. For each case report discussed, computerised tomography (CT) and digital subtraction angiography (DSA) findings are given, to better highlight the diagnostic role of these techniques in the detection and characterization of intracranial haemorrhage.

Real-Time Imaging and Detection of Intracranial Haemorrhage by Electrical Impedance Tomography in a Piglet Model

The aim of this study was to use electrical impedance tomography (EIT) to detect and image acute intracranial haemorrhage (ICH) in an animal model. Blood was infused into the frontal lobe of the brains of anaesthetized piglets and impedance was measured using 16 electrodes placed in a circle on the scalp. The EIT images were constructed using a filtered back-projection algorithm. The mean of all the pixel intensities within a region of interest--the mean resistivity value (MRV)--was used to evaluate the relative impedance changes in the target region. A symmetrical index (SI), reflecting the relative impedance on both sides of the brain, was also calculated. Changes in MRV and SI were associated with the injection of blood, demonstrating that EIT can successfully detect ICH in this animal model. The unique features of EIT may be beneficial for diagnosing ICH early in patients after cranial surgery, thereby reducing the risk of complications and mortality.

Diagnostic efficacy of handheld devices for emergency radiologic consultation.

Orthopedic injury and intracranial hemorrhage are commonly encountered in emergency radiology, and accurate and timely diagnosis is important. The purpose of this study was to determine whether the diagnostic accuracy of handheld computing devices is comparable to that of monitors that might be used in emergency teleconsultation. Two handheld devices, a Dell Axim personal digital assistant (PDA) and an Apple iPod Touch device, were studied. The diagnostic efficacy of each device was tested against that of secondary-class monitors (primary class being clinical workstation display) for each of two image types-posteroanterior wrist radiographs and slices from CT of the brain-yielding four separate observer performance studies. Participants read a bank of 30 wrist or brain images searching for a specific abnormality (distal radial fracture, fresh intracranial bleed) and rated their confidence in their decisions. A total of 168 readings by examining radiologists of the American Board of Radiology were gathered, and the results were subjected to receiver operating characteristics analysis. In the PDA brain CT study, the scores of PDA readings were significantly higher than those of monitor readings for all observers (p < or = 0.01) and for radiologists who were not neuroradiology specialists (p < or = 0.05). No statistically significant differences between handheld device and monitor findings were found for the PDA wrist images or in the iPod Touch device studies, although some comparisons approached significance. Handheld devices show promise in the field of emergency teleconsultation for detection of basic orthopedic injuries and intracranial hemorrhage. Further investigation is warranted.

Pituitary apoplexy: evaluation, management, and prognosis

To review the current standard of care in the diagnosis and treatment of pituitary apoplexy and to determine any updated clinical management strategies. Pituitary apoplexy is a rare but life-threatening medical emergency. Presenting signs and symptoms often include severe headache, visual loss, ophthalmoplegia, altered consciousness, and impaired pituitary function. Common predisposing factors include closed head trauma, blood pressure alterations, history of pituitary irradiation, cardiac surgery, anticoagulation, treatment with dopamine agonists, pituitary stimulation testing, and pregnancy. MRI imaging is the most sensitive sequence for the detection of acute and old intracranial hemorrhage. Patients often require emergent intravenous fluids, blood transfusions, and high-dose corticosteroids. Patients who remain clinically and neurologically unstable require urgent transsphenoidal surgical decompression as definitive treatment. In patients with pituitary apoplexy, improvement in visual field defects, visual acuity, and diplopia is typically observed after emergent application of therapy, often including medical and surgical treatment. Some patients may require long-term hormonal therapy after surgery.

Neuroimaging of traumatic brain injury

In this article, the neuroradiological evaluation of traumatic brain injury is reviewed. Different imaging strategies in the assessment of traumatic brain injury are initially discussed, and this is followed by a review of the imaging characteristics of both primary and secondary brain injuries. Computed tomography remains the modality of choice for the initial assessment of acute head injury because it is fast, widely available, and highly accurate in the detection of skull fractures and acute intracranial hemorrhage. Magnetic resonance imaging is recommended for patients with acute traumatic brain injury when the neurological findings are unexplained by computed tomography. Magnetic resonance imaging is also the modality of choice for the evaluation of subacute or chronic traumatic brain injury. Mild traumatic brain injury continues to be difficult to diagnose with current imaging technology. Advanced magnetic resonance techniques, such as diffusion-weighted imaging, magnetic resonance spectroscopy, and magnetization transfer imaging, can improve the identification of traumatic brain injury, especially in the case of mild traumatic brain injury. Further research is needed for other advanced imaging methods such as magnetic source imaging, single photon emission tomography, and positron emission tomography.

Effect of a Computer-aided Diagnosis System on Clinicians’ Performance in Detection of Small Acute Intracranial Hemorrhage on Computed Tomography

To analyze the effect of a computer-aided diagnosis (CAD) system on clinicians' performance in detection of small acute intracranial hemorrhage (AIH) on computed tomography (CT). The authors have developed a CAD scheme that used both image processing techniques and anatomic knowledge based classification system to improve diagnosis of small AIH on CT. A multiple-reader, multiple-case receiver operating characteristic (ROC) study was performed. Twenty clinicians, including seven emergency physicians, seven radiology residents, and six radiology specialists were recruited as readers of 60 sets of brain CT, including 30 cases that show AIH smaller than 1 cm, and 30 controls. Each reader read the same 60 cases twice, first without, then with the prompts produced by the CAD system. The clinicians ranked their confidence in diagnosing a case of showing AIH, which produced the ROC curves. Significantly improved performance is observed in emergency physicians, average area under the ROC curve (Az) increased from 0.8422 to 0.9294 (P = .0107) when they make the diagnosis without and with the support of CAD. Az for radiology residents increased from 0.9371 to 0.9762 (P = .0088). Az for radiology specialists increased from 0.9742 to 0.9868, but was statistically insignificant (P = .1755). CAD can improve the clinicians' performance in detecting AIH on CT. In particular, emergency physicians can benefit most from the CAD and improve their performance to a level approaching that of the average radiology residents.

Assessment of Hemorrhage in Pituitary Macroadenoma by T2*-Weighted Gradient-Echo MR Imaging

Intratumoral hemorrhage occurs frequently in pituitary macroadenoma and manifests as pituitary apoplexy and recent or old silent hemorrhage. T2*-weighted gradient-echo (GE) MR imaging is the most sensitive sequence for the detection of acute and old intracranial hemorrhage. T2*-weighted GE MR imaging was used to investigate intratumoral hemorrhage in pituitary macroadenomas. Twenty-five consecutive patients who underwent total or subtotal resection of pituitary macroadenoma with heights from 17 to 53 mm, including 1 patient with classic pituitary apoplexy, underwent MR imaging before surgery, including T2*-weighted GE MR imaging. For histologic assessment of the hemorrhage in whole surgical specimens, we used hematoxylin-eosin staining. T2*-weighted GE MR imaging detected various types of dark lesions, such as "rim," "mass," "spot," and "diffuse" and combinations, indicating clinical and subclinical intratumoral hemorrhage in 12 of the 25 patients. The presence of intratumoral dark lesions on T2*-weighted GE MR imaging correlated significantly with the hemorrhagic findings on T1- and T2-weighted MR imaging (P < .02 and <.01, respectively), and the surgical and histologic hemorrhagic findings (P < .001 and <.001, respectively). T2*-weighted GE MR imaging could detect intratumoral hemorrhage in pituitary adenomas as various dark appearances. Therefore, this technique might be useful for the assessment of recent and old intratumoral hemorrhagic events in patients with pituitary macroadenomas.

Overnight Preliminary Head CT Interpretations Provided by Residents: Locations of Misidentified Intracranial Hemorrhage

Our aim was to determine the patterns of error of radiology residents in the detection of intracranial hemorrhage on head CT examinations while on call. Follow-up studies were reviewed to determine if there was any adverse effect on patient outcome as a result of these preliminary interpretations. Radiology residents prospectively interpreted 22,590 head CT examinations while on call from January 1, 2002, to July 31, 2006. The following morning, the studies were interpreted by staff neuroradiologists, and discrepancies from the preliminary report were documented. Patients' charts were reviewed for clinical outcomes and any imaging follow-up. There were a total of 1037 discrepancies identified, of which 141 were due to intracranial hemorrhage. The most common types of intracranial hemorrhage that were missed were subdural and subarachnoid hemorrhage occurring in 39% and 33% of the cases, respectively. The most common location for missed subdural hemorrhage was either parafalcine or frontal. The most common location of missed subarachnoid hemorrhage was in the interpeduncular cistern. There was 1 case of nontraumatic subarachnoid hemorrhage that was not described in the preliminary report. Fourteen patients were brought back to the emergency department for short-term follow-up imaging after being discharged. We did not observe any adverse clinical outcomes that resulted from a discrepant reading. Discrepancies due to intracranial hemorrhage are usually the result of subdural or subarachnoid hemorrhage. A more complete understanding of the locations of the missed hemorrhage can hopefully help decrease the discrepancy rate to help improve patient care.

Early detection of life-threatening intracranial haemorrhage using a portable near-infrared spectroscopy device

To determine whether infrared spectroscopy allows early recognition of epidural and subdural haematomas among trauma patients. Injured people admitted to two trauma units were enrolled in a prospective multicentre observational study, and infrared spectroscopy was performed before computed tomography of the head as a part of their initial evaluation. Subsequent CT findings suggestive of epidural or subdural haematoma served as controls. Over 12 months, 110 patients were enrolled; 64 (58.1%) were men and 46 (41.9%) were women. Mean age was 56.2 years, and mean Glasgow Coma Scale on admission was 12.6. Infrared spectroscopy was 90.5% sensitive and 95.5% specific for epidural and subdural haematoma. Positive and negative predictive values were 82.6% and 97.7%, respectively. Infrared spectroscopy allows early recognition of epidural and subdural haematomas in trauma cases. Further studies are needed to evaluate whether immediate confirmation or exclusion of epidural and subdural haematomas with portable near-infrared spectroscopy devices improves the decision-making process in the treatment of severely injured people.

A Lancet Issue Devoted to Stroke

Marc Fisher MD Kennedy Lees MD Section Editors: The dominant theme of the January 27, 2007 issue of Lancet is stroke. In a new editorial policy the Lancet decided to publish themed issues of particular interest to both general clinicians and specialist researchers. Stroke is undoubtedly a disease that requires special attention: approximately 1% of the 6.5 billion people living on our planet—twice the population of Canada or 8 times the population of Switzerland—will die each year of stroke. Many of these strokes are either preventable or could be delayed to a more advanced age. Considering such figures, the Lancet editors have to be congratulated for their decision, which is an important step in the struggle to reduce the burden of stroke in our societies. They have carefully selected original articles, seminars, and reviews on stroke. In the following we will comment on the 4 original articles. ### Wahlgren N, Ahmed N, Davalos A, Ford GA, Grond M, Hacke W, Hennerici MG, Kaste M, Kuelkens S, Larrue V, Lees KR, Roine RO, Soinne L, Toni D, Vanhooren G, for the SITS-MOST investigators. Thrombolysis with alteplase for acute ischemic stroke in the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST): an observational study. Lancet. 2007;369:275–282. The European Agency for the Evaluation of Medicinal Products (EMEA) mandated a postlicensing observational registry of thrombolysis use in Europe as a condition of licensing. The web-based SITS-MOST registry was launched in response to this need and collected more than 6000 patients from nearly 300 European centers. #### Methods Any European center was eligible as long as they agreed to enter all consecutive patients and agreed to site monitoring and aggregrate data reporting. Both experienced and inexperienced thrombolysis sites were eligible. The primary outcomes were safety outcomes: symptomatic ICH and death at 3 months from treatment. #### Results Patients enrolled in the registry were typically similar to those enrolled in prior trials and stroke thrombolysis registries. The mortality rate was 11.3% and symptomatic ICH rate 7.3%. Excellent functional outcome was achieved in 39% of patients. #### Interpretation This experience represents the largest stroke thrombolysis registry globally. It documents the safety and effectiveness of alteplase for stroke in routine clinical …

Detection of unanticipated intracranial hemorrhage during intraoperative magnetic resonance image–guided neurosurgery

The authors report unanticipated intraoperative intracranial hemorrhaging in two pediatric neurosurgical patients. Both children were undergoing elective craniotomies with the aid of intraoperative magnetic resonance (iMR) imaging. In both cases, the ability of iMR imaging to aid in diagnosis allowed prompt and definitive treatment of potentially life-threatening complications. These cases illustrate the ability of iMR imaging to aid in differentiating unexpected and/or unexplained intraoperative events in pediatric neurosurgery.